I. Field of the Invention
The present invention relates to a cleat or spike for an athletic shoe and particularly to a non-metal, composite cleat for a golf shoe constructed from two or more polymeric materials having different densities and/or hardnesses.
II. Background
Spikes or cleats for athletic shoes have long been used to provide traction in dirt and grass. Such spikes or cleats typically have been made of metal or other relatively hard materials.
Shoe cleats or spikes, particularly those that are removable or replaceable, have been known in the art for at least the last 80 years. Supplemental sole protectors that attach to a shoe have also been known for over 100 years.
As early as 1891, prior artisans recognized the need for a supplemental traction device that could be attached to the bottom of a shoe. In 1891, Lithgow received U.S. Pat. No. 461,103 for such a sole protector.
U.S. Pat. No. 1,237,451 to Baldwin, issued in 1817 for a supplemental traction device. Baldwin discloses on the front page of the patent, a cleat having a circular base and a plurality of transverse ribs that extend radially outward from a center stud or head. Baldwin describes the ribs as being useful for gripping the ground to enable a golfer to assume a,steady position while making a drive.
In 1918, Studer received French Patent No. 493,748 for a cleat having a circular base with a plurality of straight, radially extending ridges. The ridges of Studer project inwardly from the outer circumference to a raised central area. Moreover, Studer incorporated a threaded member on the cleat to screw into a shoe sole.
In 1940, U.S. Pat. No. 2,185,397 issued to Birchfield for an athletic shoe cleat. The cleat of this patent is circular and utilizes a collection of radially extending straight ribs having flat tops. The cleats may be formed of a hard rubber material.
U.S. Pat. No. 2,509,980 to McCallum, which issued in 1950, discloses a removable shoe cleat for use with golf shoes. The cleat has a circular or disk-like base. The cleat has a conical stud portion with a plurality of channels having rounded interiors. In addition, the cleat has three curved wings that radiate out from the center and which provide for the optimal gripping of surfaces. The cleat comprises a threaded member that screws into an aperture along the underside of a shoe.
U.S. Pat. No. 2,895,235 to Melchiona, issued in 1959, describes a removable spike for use on sport shoes, such as golf shoes. The spike has a circular base and externally projecting ribs radially extending from the boss or slightly raised center portion of the spike. The ribs have curved sides or edges. The spike, which is stamped from metal, has a threaded member that screws into an aperture on the bottom of a shoe.
In 1970, U.S. Patent No. 3,512,275 was issued to Leavitt for a xe2x80x9cnon-penetratingxe2x80x9d cleat arrangement. As shown in the figures of this patent, the cleat arrangement utilizes a plurality of straight, (actually broken-line) radially extending flat top ridges.
More recently, various structures for cleats have been suggested including cleats having a metal or ceramic insert center surrounded by an elastomeric material. However, it was often found when using such cleats on athletic surfaces, particularly artificial turf, that the cleats of an athletic shoe would be subject to increased wear due to the harder insert supported by a relatively softer cleat body. U.S. Pat. No. 4,833,796, to Flemming discloses one example of such an arrangement. In this arrangement, a relatively stiff elastic cleat body holds a ceramic insert. In this manner, the ceramic portion, which is relatively very hard, makes contact with the playing surface, while the supporting elastic cleat body allows for flexibility and therefore less stressful dynamic loading of the athlete""s foot.
Flemming""s cleat, however, does not solve a problem often encountered by golfers. That is the need to walk not just over greens, but also over smooth hard surfaces peripheral to the playing area. Like traditional metal cleats, on a hard surface, the Flemming cleat provides little traction and also does not address the additional problems of scratching the surfaces that are walked on, which in some areas peripheral to a golf course is of some concern.
More recently, the golf cleat industry has focused on an alternative to the more commonly used metal golf spikes. The newer alternative spikes or cleats are typically formed from a non-turf penetrating, resilient polymeric material. These alternative cleats are often described as being xe2x80x9cgreen-friendlyxe2x80x9d because of their non-turf penetrating nature. In addition to being xe2x80x9cgreen-friendlyxe2x80x9d, the alternative. cleats have been found to be easier on the human body compared to previously used metal cleats.
In Nov. 1993, U.S. Pat. No. 5,259,129 was issued to Deacon, et al. This patent is directed to an alternative golf cleat formed of a resilient plastic material which, according to Deacon, et al. xe2x80x9cprovides traction but does not damage the surface being walked upon.xe2x80x9d
Since 1993, a wide variety of utility and design patents have been issued by the U.S. Patent and Trademark Office which are directed to various alternative cleat configurations.
Clearly, from the foregoing sampling of prior art, it will be appreciated that removable shoe cleats or spikes, both metal and polymeric, are well known in the art, further, prior artisans have for many years, provided such cleats with a circular or disk-like base portion having a threaded member extending traversely therefrom. The threaded member screws into an aperture on the bottom of a shoe or boot.
However, in spite of the variety of alternative cleats now available, improvements in cleats for athletic shoes, and particularly for golf shoes, are still being sought.
The present invention provides a cleat comprising a stud with a composite body for an athletic shoe that provides traction both on hard and smooth surfaces and on greens in a relatively non-penetrating manner. In accordance with one aspect of the instant invention, an exchangeable cleat having a non-metal body is provided. The non-metal body is formed of a material having first durometer (or hardness) and has a central portion formed of a material having a second durometer (or hardness). The central portion preferably extends a short distance away from a disk of surrounding material having a different durometer than the central portion, allowing (in one embodiment) a gripping central area for walking on harder surfaces. The wider, surrounding cleat provides traction on the turf, for example, during a golf swing.
In further accordance with the invention, the removable cleat can be used year-round in golf without sacrificing performance and while providing damage avoidance to greens.
The invention also includes athletic shoes provided with a plurality of dual-density cleats. Preferably, the cleats have a body that is long wearing and slip resistant by utilizing polymers and/or plastics. The non-metal, central portion preferably extends only a short distance beyond a surrounding turf-gripping portion, and provides non-penetrating but effective traction, e.g., during a golf swing.
An additional embodiment includes a non-metal cleat having enhanced turf gripping properties which are imparted by a plurality of traction elements having arcuate ridges which grip or xe2x80x9cbitexe2x80x9d the turf during a golf swing.
A further embodiment of the invention provides for an abrasive material to be incorporated into or onto either or both of the material of a first durometer and material of a second durometer utilized in the non-metal body of the cleat.
In preferred embodiments of the invention, the materials are selected to provide a long wearing, slip-resistant, non-metal golf cleat that alleviates damage to the surface of a golf green, yet provides traction on grass and wears similar to conventional metal spikes.
These and other objects and features of the invention will be apparent from the following description and from the claims.